The present invention relates to a geared motor and a power window device that includes a geared motor as a drive source.
Japanese Laid-Open Patent Publication No. 2013-108549 discloses an example of a geared motor including a motor and a reduction drive, which are integrally coupled to each other. A gear housing of the reduction drive includes a support shaft, a speed reduction-output member is rotationally supported by the support shaft. The speed reduction-output member includes a reduction gear (worm wheel in the above publication) that reduces a rotation speed of the motor and an output gear that is rotatable integrally with the reduction gear. The support shaft is fitted into the speed reduction-output member and inserted through the reduction gear and the output gear. The output gear of the speed reduction-output member is meshed with an input member, which is located outside the geared motor. Thus, the rotation produced by the motor is reduced in speed by the reduction gear and transmitted from the output gear to the input member.
Further, the geared motor includes a restriction portion. The restriction portion, which is accommodated in an accommodation recess of the output gear, restricts separation of the speed reduction-output member from the support shaft. The support shaft is inserted into the accommodation recess, and the restriction portion is located in a radial direction between an outer circumferential surface of the support shaft and an inner circumferential surface of the accommodation recess. The restriction portion is fixed to the support shaft and engaged with the accommodation recess of the speed reduction-output member in an axial direction of the support shaft. Thus, the restriction portion restricts movement of the speed reduce ion-output member relative to the support shaft.
However, in the above geared motor, when the output gear of the speed reduction-output member receives stress in the radial direction from the input member, the radial stress may be transmitted through the restriction portion to the support shaft and damage the support shaft.